Undersea well test tree control valve and system

ABSTRACT

As part of a subsea well system, a hydraulically actuated and sequentially opening and closing control valve incorporating an upper rotary valve actuated by a rack and pinion or linear actuator arrangement coupled with a lower valve actuated by a stinger or mandrel arrangement whereby the lower valve is opened before the rotary valve is opened and the rotary valve is closed before the lower valve is closed. The lower valve may be of the flapper type. The valve incorporates a hydraulic operator actuated in one direction to open the valve by application of hydraulic pressure from a remote source, and actuated in the reverse direction to close the valve by resilient springs and/or by subsea hydrostatic pressure. The valve may also be closed by closing the rams of the blowout preventer in the subsea system above the valve and applying pressure through the kill line of such blowout preventer.

United States'Patent 11 1 Scott UNDERSEA WELL TEST TREE CONTROL VALVE AND SYSTEM inventor: Lyle B. Scott, South Gate, Calif.

Assignee:

Calif.

Jan. 21, 1911 Filed:

Appl. No.:

References Cited UNITED STATES PATENTS 7/1967 ..l3 7/614.ll 5/1966 ....l37/630.l9 X 6/1971 ....137/630.19 11/1963 Lewis Berryman Byron Jackson Inc., Long Beach,

3,724,501 Apr. 3, 1973 Primary Examiner-Robert G. Nilson [57] ABSTRACT As part of a subsea well system, a hydraulically actuated and sequentially opening and closing control valve incorporating, an upper rotary valve actuated by a rack and pinion or linear actuator arrangement coupled with a lower valve actuated by'a stinger or mandrel arrangement whereby the lower valve is opened before the rotary valve is opened and the rotary valve is closed before the lower valve is closed. The lower valv-e maybe of the flapper type. The valve incorporates a hydraulic operator actuated in one direction to open the valve by application of hydraulic pressure from a remote source, and actuated in the reverse direction to close the valve by resilient springs and/or by subsea hydrostatic pressure. The valve may also be closed by closing the rams of the blowout preventer in the 'subsea system above the valve and applying pressure through the kill line of such blowout preventer.

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UNDERSEA WELL TEST TREE CONTROL VALVE AND SYSTEM BACKGROUND OF THE INVENTION This invention generally concerns drill stem testing and the like from a floating drilling vessel and more particularly to a subsea test tree including an improved safety control valve, commonly referred to as a failsafe valve, having valve elements actuated in sequence or tandem.

Operations such as drill stem testing require a reliable and safe shut down technique to rapidly disconnect from a subsea well and secure the well should it become necessary to move the surface vessel off the well location due to bad weather or other adverse conditions. In such operations a fail-safe valve is located in the pipe string within or slightly below the subsea blowout preventer stack assembly. This valve is held open with hydraulic pressure and should automatically close when such pressure is released. It is desirable that the fail-safe valve include at least two valve elements with one such valve element serving as back up for the other valve element. Since the well may be flowing fluids containing particulate and sometimes abrasive materials when shut-off or opening is effected, it is desirable that the valve elements be actuated sequentially so that one of such valve elements initially effects such shut-off, requiring exposure to the erosive effects of the flowing fluid, and the other of such valve elements follows into positively sealing position after fluid flow has completely or substantially terminated.

For rapid disconnection of the suspended well pipe string from the subsea equipment and ready reconnection of the pipe string to the subsea equipment, a suitable quick release-reconnect coupling is provided such as shown in U.S. Pat. No. 3,488,031, such a coupling- No. 2,238,609 No. 2,7ss,753 No. 3,035,808

Rotary valves which are variously related to the rotary valve incorporated in the invention as disclosed herein are shown in the following U.S. Pats., for example:

No. 2,894,715 Y I No. 2.993070 No. Re. 25,471 M r n 2,950,187 3,126,908 3.189.044 3,233,860 3,236,255 3,292,706 3,310,114 3,457,991 3,509,913

Flapper check valves of the-kind incorporated in the invention as disclosed herein are shown in the following US, Pats., for example:

No. 2,912,216 No. 3,094,170 No. 3,035,641 3,265,134 3,412,806 3,411,576 3,398,762 3,200,837 2,998,077 3,332,497 3,218,024 3,107,080 3,104,862 2,963,260

Structures considered as most pertinent examples to an understanding of the invention as disclosed herein are shown in U.S. Pats. No. 3,488,031 and No. 3,502,913, and on pages 3790-3791 of the COM- POSITE CATALOG referenced above.

SUMMARY OF THE INVENTION An object of this invention is to provide a fail-safe control valve having at least two valve elements operative in succession or sequence so that at least one of such valve elements is protected from fluid erosion while maintaining the safety features of multiple valves.

Another object of this invention is to provide a failsafe valve which may be closed in an emergency by any or all of three separate means of closure.

A further object of this invention is to provide a valve, comprised of common and simple components for relatively inexpensive manufacture and maintenance.

The foregoing and other conditions and objects are met with a control valveapparatus for use in subsea operations having a tubular valve body adapted for connection into a well pipe, a mandrel member extending through the body and providing a flow passage through the well pipe, a first and a second valve ele ment mounted within the valve body to be operative between an open and a closed position responsive to axial movement of the mandrel within the body, the

first and said second valve element being mounted within the body with means responsive to axial movement of the mandrel to (a) first completely open the first valve element while the second valve element BRIEF DESCRIPTION or Tl-IEDRAWING FIG. 1 is an elevational, partly sectional, view of a pipe string suspended from the water surface (not shown) and connected to a subterranean well pipe through a release-reconnect coupling and through a control valve shown in open position which is mounted within a schematically shown blowout preventer stack assembly. I

FIG. 2 is the elevational view of FIG. 1 wherein the coupling has been disconnected and the control valve moved to a closed position.

FIG. 3 is a longitudinal sectional view of a major portion of the control valve of the invention shown in closed position;

FIG. 4 is a longitudinal sectional view of a portion of the control valve of the invention shown in an intermediate position as found during the closing cycle or the opening cycle of the valve.

FIG. 5 is a longitudinal sectional view taken along the line 55 of FIG. 3.

FIG. 6 is a transverse sectional view taken along the line 6-6 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, there is shown subsea apparatus 10 mounted on a well head 12 extending from the sea floor 14. Subsea apparatus 10 includes a blowout preventer stack assembly 16 having removably mounted thereon a riser latch assembly 18. Riser latch assembly 18 is connected to a riser or conductor pipe 20 which extends upwardly to floating surface equipment (not shown).

A control valve 22, hereinafter described, is threadedly connected at its lower end to a landing collar 24 which is supported by one set of a plurality of rams 26 mounted within blowout preventer stack 16. Landing collar 24 is threadedly connected to a well pipe 28 which extends into connection with well head equipment (not shown) mounted within well head 12.

The set of rams 26 supporting landing collar 24 is also closed around well pipe 28 and effects a seal between the interior of well head 12 and blowout preventer stack 16. The upper end of control valve 22 is threadedly connected through a conduit sub 30 into a quick type release coupling member 32. Coupling 32 is threadedly connected to the lower end of a pipe string 34 which extends upwardly to such floating surface equipment and is suspended therefrom.

A flexible hydraulic conduit 36 is connected at its lower end to the upper end of coupling 32 and at its upper end to a surface source of fluid pressure. Hydraulic fluid pressure is also supplied into the top of control valve 22, later described, through a flexible hydraulic conduit 38 extending from a surface pressure source and connected to the upper end of coupling 32, through a passageway 40 longitudinally defined through coupling 32 and through a flexible hydraulic conduit 42 connected between the lower end of coupling 32 in communication with passage 40 and the upper end of control valve 22 to provide fluid communication into valve 22.

Briefly described, coupling member 32 includes a mandrel member 44 provided with a latch recess 46 and threadedly connected to sub 30 as shown and a sleeve member 48 threadedly connected to pipe string 34 and fitted about mandrel 44. When fitted as shown, a stinger member 50 extends into mandrel 44 and complementary portions of passageway 40, defined in each of members 44 and 48, are joined in fluid communication. Coupling member 32 also includes a latch sleeve 52 and a lug sleeve 54 mounted as shown with appropriate recesses to accommodate a latch dog 56 and a lug 58, mounted as shown. As provided, sleeve 48 is releasably latched to mandrel 44, after being slipped over the mandrel, and the sleeve is subsequently released for removal from the mandrel when actuated by application of fluid pressure through conduit 36 onto the upper area of latch sleeve 52. Apparatus such as coupling member 32 is disclosed in detail in U.S. Pat. No. 3,488,031, specifically incorporated herein by reference.

Referring additionally to FIGS. 3-6, control valve 22 has a generally tubular body 60 including an upper connection member 62 and a lower connection member 64. Upper connection member 62 is threadedly connected to conduit sub 30 and lower connection member 64 is threadedly connected through a valve retainer sub 66 to landing collar 24. Ports 61 provide fluid communication between the interior and exterior of body 60.

Extending through valve'22 is a composite hollow mandrel member 67 comprising an upper seal mandrel 68, a piston 70, a driving mandrel 72, a spring return plate 74, a valve body 76 and a lower actuating mandrel or stinger 78. Piston 70 is mounted on driving mandrel 72 and retained in operative position by threaded connection of seal mandrel 68 with driving mandrel 72. Driving mandrel 72 and valve body 76 are shown as being integral in structure but may be separate components with threaded connection if desired. Retainer plate 74 is mounted with valve body 76 and fastened into position by threaded connection of a spanner nut 80. Piston 70 is fitted into a cylinder 82 which cylinder is concentrically mounted and threadedly connected into upper connection member 62. Connection member 62, seal mandrel 68, piston 70 and cylinder 82 as provided cooperate to define a hydraulic chamber 84 which is in fluid communication with hydraulic line 42 through a passageway 86 defined in connection member 62. Appropriate seals such as O-rings are provided about seal mandrel 68, piston 70 and driving mandrel 72 to confine fluids under pressure within chamber 84 and also to seal the interior of mandrel assembly 67 from the exterior of valve body 22.

To limit downward movement of piston 70 within cylinder 82, a limit bushing 88 is mounted in threaded connection within the lower end of cylinder 82. As provided, the extreme upper and lower positions of piston 70, and consequently the entire mandrel assembly 67, is limited in predetermined relation within valve 22 by upper connection member 62 and limit bushing 88, respectively.

Valve body 76 may be generally a hexahedron in shape as shown and is supported against rotation within body 60 by valve guides 90 and 91 which guides are mounted within body 60 by means such as cap screws (not shown). When valve 22 is assembled, mandrel assembly 67 is forcibly urged to its upper position within body 60 by means of springs 92 longitudinally mounted in compression between return plate 74 and lowerconnection member 64. Springs 92 aremaintained in longitudinal position by means of guide rods 94 projecting from return plate 74, by guide rods 96 projecting from connection member 64 and by guide holes 98 defined through guides 90 and 91 as shown in FIGS. 3 and 6.

Referring to FIGS. 1-6, valve body 76 is shown to house a rotary valve member or plug 100 which plug is adapted to be rotated between an open position and a closed position. Plug 100 is retained in operative position within body 76 by means of a retainer bushing 102 having threaded connection within body 76, as shown in FIGS. Sand 6. Plug 100 is fitted within an intermediate seal sleeve 101 mounted within body 76. Seal means such as O-ring guides 104 and O-rings 106 are mounted about plug support shafts 108 and 110 extending from plug 100 and between the plug and body 76. Plug shaft 110 is fitted with an operator 112 which is secured thereon by a threaded nut 114.

An arcuate slot 116 is developed in a portion of operator 1 12 which accommodates a limit pin] 17 connected into valve body 76, as shown in FIGS. 3-5. The slot 116 and pin 1 17 function to limit plug 100 between a fully open and a fully closed position. Another portion of operator 112 is developed into a segment of a gear pinion 118, as shown in FIGS. 36..Gear pinion 118 is adapted to engage a gear rack 120 which is developed as a portion of guide91. As mandrel 67 is moved downwardly, pinion l18'initially engages rack 120. Further movement to the position limit established by limit bushing 88 causes meshing of the gears and rotation of operator 112 which rotates plug 100 from the closed to the open position. It is to be noted that mandrel assembly 67 must be moved downwardly a predetermined distance before pinion 118 and rack 120 mesh and become operable to cause rotation of plug 100.

As best shown in FIGS. 3 and 4, actuating stinger 78 is adapted to extend through lower connector member 64. Appropriate seal means such as O-rings are mounted between stinger 78 and member 64 to effect a seal between the interior of mandrel assembly 67 and the outside of valve 22. Stinger 78 is threadedly connected into valve body 76 as shown and tack welded or otherwise fixed in arcuate orientation with respect to the valve body.

A valve cage assembly 122 is mounted in intermediate relation by and between valve retainer sub 66 and connection member 64. Cage assembly 122 has pivotally mounted therein a swing type valve member 124 mounted by means of a spring and pivot assembly 125. Cage assembly 122 includes a valve seat 121 with an appropriate seal such as an O-ring. Valve cage 122 and valve 124 is arcuately oriented with respect to connection member 64, and consequently with respect to valve body 76 and stinger 78, by means of an alignment dowell pin 126 fitted into adjacent portions of cage 122 and member 64. A curved bevel 128 is developed across the lower end of stinger 78 which purpose is to engage valve member 124 across from pivot assembly 125 then push valve 124 from the closed to the open position in a rolling and sliding fashion as stinger 78 is moved downwardly into valve cage 122.

OPERATION OF THE PREFERRED EMBODIMENT In operation, valve 22, landing collar 24 and release coupling 32 are installed within blowout preventer 16 with lower rams 26 closed as shownin FIG. 1. Hydrau-l lic fluid is forced under pressure into chamber 84 through conduits 38, 40 and 42, causing piston 70 and mandrel assembly 67 to move from their upper position to their lower position established by limit bushing 88.

Initial downward movement of assembly 67 and stinger 78 causes valve member 124 to move from its closed position to its open position (FIG. 4). At this stage plug 100 has not been actuated and remains in closed position. Continued downward movement of mandrel as sembly 67 causes pinion 118 to mesh with rack 120 then rotate plug 100 from its closed to its open posi-' tion, whereupon further movement of mandrel assembly 67 is stopped by contact of piston 70 with limit bushing 88.

It is to be noted that such structure and operation as described permits valve 124 to be fully opened and thus to be exposed to a minimum of abrasive flow contact with possibly erosive fluids flowing through well pipe 28 before any such flow is permitted by subsequent opening of valve plug 100. Any fluid caused erosion thus will be confined to plug 100 and to some extent to sleeve 101.

When it is desired to release sleeve member 48 and latch assembly 18 from the remainder of the subsea installation, as caused by an emergency or for any other reason, pressure is released from chamber 84 of valve 22 through conduit 38, or subsequent disconnection of coupling 32, and fluid pressure is applied through conduit 36 to bear on latch sleeve 52 and unlock sleeve member 48 from mandrel member 44. Latch assembly 'valve when necessary.

18 and pipe string 34 including sleeve member 48 is thereafter removed from stack assembly 16.

When closure of valve 22 is desired, three features are available to insure closure of the valve. The first closing feature is the compression springs 92 which forcibly urge the valve to a closed position when fluid pressure in chamber 84 is reduced. As a second closing feature, when fluid pressure through conduit 38 is released and before coupling 32 is disconnected, the hydrostatic pressure of the sea water around valve 22 is greater than that of the hydraulic fluid in chamber 84 and such pressure is communicated through body parts 61 to the underside of piston to urge the valve closed. As a third feature in closing the valve, one of the upper set of rams 26 may be closed about the top of valve 22 (FIG. 2) and fluid pressure may be introduced into blowout preventer stack 16 through its control system (not shown) which fluid pressure is communicated through ports 61 to the underside of piston 70 to close the valve.

It is to be noted, while the flapper type valve cage assembly is disclosed herein as a preferred embodiment, that other properly spaced valve means actuated by mandrel assembly 76 could be provided. As an example, a second properly spaced rotary valve, pinion and I rack assembly such as shown herein could be provided. The desirable features to be provided by this invention are the sequential opening and closing of at least two valve elements along with positive means to close the While only one embodiment of the invention is shown and described herein, other embodiments and variations thereof will become apparent to be included in the spirit of the invention as herein set forth.

That being claimed is:

1. A subsea control valve comprising:

a. an elongated valve body adapted for connection into a conduit;

b. actuating fluid flow mandrel, means mounted within said body for movement between first and second positions within said body;

c. hydraulic actuating means connected with said body and said mandrel means and operative to move said mandrel means between said first and said second positions;

. first valve means mounted within said body and operative to be opened by movement of said mandrel means from said first position to said second position;

. second valve means mounted within said body and operative to remain closed until said first valve means has been fully opened by movement of said mandrel means then to be opened in sequence by continued movement of said mandrel means from said first position to said second position;

. said mandrel means being operative first to fully close said second valve means and then to close said first valve means in sequence upon movement of said mandrel means from said second position within said body for movement between first and.

second positions within said body;

. hydraulic actuating means connected with said body and said mandrel means and operative to move said mandrel means between said first and said second positions;

. first valve means mounted within said body and operative to be opened by movement of said mandrel means from said first position to said second position;

. second valve means mounted within said body and operative to remain closed until said first valve means has been fully opened by movement of said mandrel means then to be opened in sequence by continued movement of said mandrel means from said first position to said second position;

. said mandrel means being operative first to fully close said second valve means and then to close said first valve means in sequence upon movement of said mandrel means from said second position to said first position;

. return means mounted between said mandrel means and said body which is operative to urge said mandrel means from said second position to said first position;

. wherein said second valve includes a rotary valve body mounted with said mandrel means, a rotary valve member mounted for rotation within said rotary valve body, and rotary actuating means to rotate said valve between opened and closed positions in response to movement of said mandrel means within said body; and

'. wherein said first valve means includes a flapper type valve mounted within said valve body to be pushed open by an extension of said mandrel 3. l 'l 1 e ontrol valve of claim 2 wherein said rotary actuating means includes a gear pinion mounted with said rotary valve member adapted to mesh with a gear rack mounted with said elongated valve body.

4. A subsea control valve comprising:

a. an elongated valve body adapted for connection into a conduit;

b. actuating fluid flow mandrel means mounted within said body for movement between first and second positions within said body;

. hydraulic actuating means connected with said body and said mandrel means and operative to move said mandrel means between said first and said second positions;

'. first valve means mounted within said body and operative to be opened by movement of said mandrel means from said first position to said second.

position;

I second valve means mounted within said body and operative to remain closed until said first valve has been fully opened by movement of said mandrel means then to be sequentially opened by continued movement of said mandrel means from said first position to said second position and vice versa whereby said first valve means and said second valve means are sequentially opened and sequentially closed upon movement of said mandrel means between said first position and said second position;

. wherein return means is provided between said mandrel means and said body which is operative to urge said mandrel from said second position to said first position; and

. wherein said first valve means includes a flapper type valve mounted on said valve body adapted to be opened by said mandrel means and wherein said second valve means includes a rotary valve body mounted with said mandrel means, a rotary valve member mounted for rotation within said body, and rotating means to rotate said valve between opened and closed positions in response to movement of said mandrel means within said body said rotating means including a gear pinion mounted with said rotary valve member and adapted to mesh with a gear rack mounted with said elongated valve body.

5. The control valve set forth in claim 4 wherein said return means includes compression springs. 

1. A subsea control valve comprising: a. an elongated valve body adapted for connection into a conduit; b. actuating fluid flow mandrel means mounted within said body for movement between first and second positions within said body; c. hydraulic actuating means connected with said body and said mandrel means and operative to move said mandrel means between said first and said second positions; d. first valve means mounted within said body and operative to be opened by movement of said mandrel means from said first position to said second position; e. second valve means mounted within said body and operative to remain closed until said first valve means has been fully opened by movement of said mandrel means then to be opened in sequence by continued movement of said mandrel means from said first position to said second position; f. said mandrel means being operative first to fully close said second valve means and then to close said first valve means in sequence upon movement of said mandrel means from said second position to said first position; g. return means mounted between said mandrel means and said body which is operative to urge said mandrel means from said second position to said first position; and h. wherein said first valve means includes a flapper type valve mounted within said valve body and adapted to be opened by said mandrel means.
 2. A subsea control valve comprising: a. an elongated valve body adapted for connection into a conduit; b. actuating fluid flow mandrel means mounted within said body for movement between first and second positions within said body; c. hydraulic actuating means connected with said body and said mandrel means and operative to move said mandrel means between said first and said second positions; d. first valve means mounted within said body and operative to be opened by movement of said mandrel means from said first position to said second position; e. second valve means mounted within said body and operative to remain closed until said first valve means has been fully opened by movement of said mandrel means then to be opened in sequence by continued movement of said mandrel means from said first position to said second position; f. said mandrel means being operative first to fully close said second valve means and then to close said first valve means in sequence upon movement of said mandrel means from said second position to said first position; g. return means mounted between said mandrel means and said body which is operative to urge said mandrel means from said second position to said first position; h. wherein said second valve includes a rotary valve body mounted with said mandrel means, a rotary valve member mounted for rotation within said rotary valve body, and rotary actuating means to rotate said valve between opened and closed positions in response to movement of said mandrel means within said body; and i. wherein said first valve means includes a flapper type valve mounted within said valve body to be pushed open by an extension of said mandrel means.
 3. The control valve of claim 2 wherein said rotary actuating means includes a gear pinion mounted with said rotary valve member adapted to mesh with a gear rack mounted with said elongated valve body.
 4. A subsea control valve comprising: a. an elongated valve body adapted for connection into a conduit; b. actuating fluid flow mandrel means mounted within said body for movement between first and second positions within said body; c. hydraulic actuating means connected with said body and said mandrel means and operative to move said mandrel means between said first and said second positions; d. first valve means mounted within said body and operative to be opened by movement of said mandrel means from said first position to said second position; e. second valve meanS mounted within said body and operative to remain closed until said first valve has been fully opened by movement of said mandrel means then to be sequentially opened by continued movement of said mandrel means from said first position to said second position and vice versa whereby said first valve means and said second valve means are sequentially opened and sequentially closed upon movement of said mandrel means between said first position and said second position; f. wherein return means is provided between said mandrel means and said body which is operative to urge said mandrel from said second position to said first position; and g. wherein said first valve means includes a flapper type valve mounted on said valve body adapted to be opened by said mandrel means and wherein said second valve means includes a rotary valve body mounted with said mandrel means, a rotary valve member mounted for rotation within said body, and rotating means to rotate said valve between opened and closed positions in response to movement of said mandrel means within said body said rotating means including a gear pinion mounted with said rotary valve member and adapted to mesh with a gear rack mounted with said elongated valve body.
 5. The control valve set forth in claim 4 wherein said return means includes compression springs. 